Ladder construction



' Feb. 20, 1968 H. B. RICH 3,369,630

LADDER CONSTRUCTION Filed Oct. 19', 1965 FIG. 5

INVENTQR 3 HOWARD B. RICH Attorneys United States Patent Ofiice 3,369,630 Patented Feb. 20, 1968 This invention relates to a ladder. More particularly, this invention relates to an improved construction for a section of an extension ladder or the like.

An object of this invention is to provide a strong stable ladder having wooden rails and tubular metal rungs.

A further object of this invention is to provide a ladder of this type in which ends of the rungs are received in annular recesses in the rails and in which beads on the rungs engage sides of the rails to cover ends of the recesses.

A further object of this invention is to provide a ladder of this type in which barbs on the rungs are driven into the wood of the rails to prevent turning of the rungs.

A further object of this invention is to provide a ladder of this type in which the barbs are of lesser height than the beads so that slots formed as the barbs are driven into the rails are covered by the beads.

The above and other objects and features of the inven tion will be apparent to those skilled in the art to which this invention pertains from the following detailed description and the drawing, in which:

FIG. 1 is a View in side elevation showing a portion of a ladder section constructed in accordance with an embodiment of this invention;

FIG. 2 is a view in section taken on the line 22 in FIG. 1;

FIG. 3 is a view in section taken on the line 3-3 in FIG. 2;

FIG. 4 is a view in section taken on the line 44 in FIG. 1;

FIG. 5 is a view in section taken on the line 5-5 in FIG. 4; and

FIG. 6 is a view in end elevation of a rung forming a part of the ladder illustrated in FIG. 1.

In the following detailed description and the drawing, like reference characters indicate like parts.

In FIG. 1 is shown a ladder section 10 having wood side rails 12 and 13. The side rails 12 and 13 are spanned by rungs 14 and 15. As shown in FIG. 3, each of the rungs is formed of metal tubing. The surface of each rung is provided with ribs 16 to prevent slipping. The material of the rung adjacent each side rail is outwardly extended to form return bent portions or flanges 17 which engage the rungs. End portions 18 of the rungs extend into annular sockets or slots 19 in the rungs. The sockets can extend more than half-way through the rails to give strong support for ends of the rungs but preferably do not extend to outer edges of the rails.

As shown in FIG. 2, the annular socket 19 is formed in the rung with a plug 20 being retained thereinside. A central bore 21 is formed in the plug 20. As already indicated, the end portion 18 (FIG. 3) of the rung is received in the annular socket, and the plug supports the interior wall of the rung.

Outboard of the flanges or beads 17, each end portion of each rung is provided with a plurality of outwardly extending barbs 22 which are driven into the wood of the rails as the rails and rungs are assembled, forming slots 23 (FIG. 3) in the rails as the barbs are driven into place. As shown most clearly in FIG. 3, the bead 17 is of greater height than the barbs 22 so that, when the rails and rungs are assembled, the bead 17 overlies the slots 23 to close ends of the slots. As shown in FIG. 2,

the barbs 22 are formed from the metal of the rungs with barbs 22 and 22a extending outwardly and in opposite directions so that the barbs lock the rungs against turning in either direction.

Selected rungs are held in assembled relation with the side rails 12 and 13 by means of tension rods 32 (only one of which is shown in FIG. 3). The tension rod 32 extends axially through the rung associated therewith and through the side rails 12 and 13. As shown in FIG. 3, the tension rod 32 extends through the bore 21 in the rail 13 coaxially with the plug 20. Washers 33 and 34 (FIG. 1) are received on the tension rod and engage outer faces of the rails 12 and 13, respectively. A head 36 at one end of the tension rod 32 engages the washer 33. A nut 37 (FIG. 3) threaded on the other end of the tension rod 32 engages the washer 34. When the nut 37 and similar nuts on other tension rods are drawn up tightly on the threaded ends of the rods, the washers are held firmly against ends of the rungs so that the rungs are held in compression and the rails and rungs are firmly secured together.

Other selected rungs are held in assembled relation with the side rails in the manner illustrated in FIGS. 4 and 5. A nail 42 passes through-the rail 13 and through the walls of the rung 14 and through a plug 20a in the rail 13. Preferably, the nail passes through the rail intermediate the barbs, as shown most clearly in FIG. 4.

In my preferred ladder construction, alternate rungs are provided with rods and other alternate rungs are nailed. However, if desired, all rungs can "be nailed or all rungs can be provided with rods.

The rungs can be formed of any suitable sturdy metal. Preferably, the rungs are formed of aluminum or magnesium. Since the rails are of wood, there is no conductivity of electricity along the ladder and no hazard of hands freezing to rails in cold weather.

The barbs on the rungs tightly grip the rails and prevent turning and loosening of the rungs.

The ladder construction illustrated in the drawing and described above is subject to structural modification without departing from the spirit and scope of the appended claims.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A ladder which comprises a pair of elongated spaced wood rails, a plurality of tubular metal rungs spanning the rails, the rails having annular sockets on their inside faces, each annular socket having a plug in fixed relation to the rail and coaxial with the socket, end portions of the rungs being received in the annular sockets, the end portions of the rungs having integral longitudinally and outwardly extending spur-flap portions of their wall bent to project from said wall, said spur-flap portions cutting grooves in the wood rails when the rung end portions are inserted in said sockets, at least one of said spur-flap portions being bent counterclockwise from the wall to projecting relation and at least another thereof being bent clockwise from the wall to projecting relation, said spurflap portions of the rungs interlockingly engaging the wood of the rails, there being outwardly extending return bent flanges on each rung engaging inner faces of the rails, the flanges extending outwardly further than the spurflap portions, the flanges overlying and closing slots formed in the rails by the spur-flap portions, and nail means extending through the rails and through end portions of the rungs intermediate the spur-flap portions for holding the rails and rungs in assembled relation.

2. A ladder which comprises a pair of elongated spaced food rails, a plurality of tubular metal rungs spanning the rails, the rails having annular sockets on their inside faces, each annular socket having a plug in fixed relation to the rail and coaxial with the socket, end portions of the rungs being received in the annular sockets, the end portions of the rungs having integral longitudinally and outwardly extending spur-flap portions of their wall bent -to project from said wall, said spur-flap portions, cutting grooves in the Wood rails when the rung end portions are inserted in said sockets, at least one of said spur-flap portions being bent counterclockwise from the wall to projecting relation and at least another thereof being bent clockwise'from the wall to projecting relation, said spurfiap portions of the rungs interlockingly engaging the wood of the rails, there being outwardly extending return bent flanges on each rung engaging inner faces of the rails, the flanges extending outwardly further than the spur-flap portions, the flanges overlying and closing slots formed in the rails by the spur-flap portions, rod means spanning the rails and extending axially of at least one of the rungs, and means on the rod means engaging the rails for holding the rails and rungs in assembled relation.

3. A ladder which comprises a pair of elongated spaced Wood rails, a plurality of tubular metal rungs spanning the rails, the rails having annular sockets on their inside faces, each annular socket having a plug in fixed relation to the rail and coaxial with the socket, end portions of the rungs being received in the annular sockets, the end portions of the rungs having integral longitudinally and outwardly extending spur-flap portions of their wall bent to project from said wall, said spur-flap portions cutting grooves in the wood rails when the rung end portions are inserted in said sockets, at least one of said spur-flap portions being bent counterclockwise from the wall to projecting relation and at least another thereof being bent clockwise from the wall to projecting relation, said spur-flap portions of the rungs interlockingly engaging the 'wood of the rails, there being outwardly extending return bent flanges on each rung engaging inner faces of the rails, the flanges extending outwardly further than the spur-flap portions, the flanges overlying and closing slots formed in the rails by the spur-flap portions, and means holding the rails and rungs in assembled relation.

References Cited UNITED STATES PATENTS 3,139,768 7/1964 Biesecker 28720 488,113 12/1892 Bushee 182228 1,162,950 12/1915 Schreiner 182228 1,250,520 12/1917 Schreiner 182228 1,531,916 3/1925 Flintjer 182228 1,729,963 10/1929 Pease 182-228 3,142,356 7/1964 Rich 182228 REINALDO P. MACHADO, Primary Examiner. 

1. A LADDER WHICH COMPRISES A PAIR OF ELONGATED SPACED WOOD RAILS, A PLURALITY OF TUBULAR METAL RUNGS SPANNING THE RAILS, THE RAILS HAVING ANNULAR SOCKETS ON THEIR INSIDE FACES, EACH ANNULAR SOCKET HAVING A PLUG IN FIXED RELATION TO THE RAIL AND COAXIAL WITH THE SOCKET, END PORTIONS OF THE RUNGS BEING RECEIVED IN THE ANNULAR SOCKETS, THE END PORTIONS OF THE RUNGS HAVING INTEGRAL LONGITUDINALLY AND OUTWARDLY EXTENDING SPUR-FLAP PORTIONS OF THEIR WALL BENT TO PROJECT FROM SAID WALL, SAID SPUR-FLAP PORTIONS CUTTING GROOVES IN THE WOOD RAILS WHEN THE RUNG END PORTIONS ARE INSERTED IN SAID SOCKETS, AT LEAST ONE OF SAID SPUR-FLAP PORTIONS BEING BENT COUNTERCLOCKWISE FROM THE WALL TO PROJECTING RELATION AND AT LEAST ANOTHER THEREOF BEING BENT CLOCKWISE FROM THE WALL TO PROJECTING RELATION, SAID SPURFLAP PORTIONS OF THE RUNGS INTERLOCKINGLY ENGAGING THE WOOD OF THE RAILS, THERE BEING OUTWARDLY EXTENDING RETURN BENT FLANGES ON EACH RUNG ENGAGING INNER FACES OF THE RAILS, THE FLANGES EXTENDING OUTWARDLY FURTHER THAN THE SPURFLAP PORTIONS, THE FLANGES OVERLYING AND CLOSING SLOTS FORMED IN THE RAILS BY THE SPUR-FLAP PORTIONS, AND NAIL MEANS EXTENDING THROUGH THE RAILS AND THROUGH END PORTIONS OF THE RUNGS INTERMEDIATE THE SPUR-FLAP PORTIONS FOR HOLDING THE RAILS AND RUNGS IN ASSEMBLED RELATION. 